Inbred corn line PHAAO

ABSTRACT

According to the invention, there is provided an inbred corn line, designated PHAA0. This invention thus relates to the plants and seeds of inbred corn line PHAA0 and to methods for producing a corn plant produced by crossing the inbred line PHAA0 with itself or with another corn plant. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line PHAA0 with another corn line or plant.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 08/187,281, filed Jan.24, 1994, now abandoned.

FIELD OF THE INVENTION

This invention is in the field of corn breeding, specifically relatingto an inbred corn line designated PHAA0.

BACKGROUND OF THE INVENTION Plant Breeding

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant.

Corn plants (Zea mays L.) can be bred by both self-pollination andcross-pollination techniques. Corn has separate male and female flowerson the same plant, located on the tassel and the ear, respectively.Natural pollination occurs in corn when wind blows pollen from thetassels to the silks that protrude from the tops of the incipient ears.

The development of a hybrid corn variety involves three steps: (1) theselection of plants from various germplasm pools; (2) the selfing of theselected plants for several generations to produce a series of inbredlines, which, although different from each other, breed true and arehighly uniform; and (3) crossing the selected inbred lines withunrelated inbred lines to produce the hybrid progeny (F₁). During theinbreeding process in corn, the vigor of the lines decreases. Vigor isrestored when two unrelated inbred lines are crossed to produce thehybrid progeny. An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between any twoinbreds will always be the same. Once the inbreds that give a superiorhybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

The objective of commercial maize inbred line development programs is todevelop new inbred lines that combine to produce high grain yields andsuperior agronomic performance in hybrid combination. The primary traitbreeders seek is yield. However, other major agronomic traits are ofimportance in hybrid combination and have an impact on yield orotherwise provide superior performance in hybrid combinations. Suchtraits include percent grain moisture at harvest, relative maturity,resistance to stalk breakage, resistance to root lodging, grain quality,and disease and insect resistance. In addition the lines per se musthave acceptable performance for parental traits such as seed yields,kernel sizes, pollen production, all of which affect the ability toprovide parental lines in sufficient quantity and quality forhybridization. Traits have been shown to be under genetic control andmany if not all of the traits are affected by multiple genes. Thus, tobe selected as an inbred line, the inbred must be able to combine suchthat the desired traits are passed to the hybrid and also be able tosatisfy production requirements as a parental line.

Pedigree Breeding

The pedigree method of breeding is the mostly widely used methodologyfor new inbred line development.

In general terms this procedure consists of crossing two inbred lines toproduce the non-segregating F₁ generation, and self pollination of theF₁ generation to produce the F₂ generation that segregates for allfactors for which the inbred parents differ. An example of this processis set forth below. Variations of this generalized pedigree method areused, but all these variations produce a segregating generation whichcontains a range of variation for the traits of interest.

EXAMPLE 1 Hypothetical Example of Pedigree Breeding Program

Consider a cross between two inbred lines that differ for alleles atfive loci.

The parental genotypes are:

Parent 1 A b C d e F/A b C d e F

Parent 2 a B c D E f/a B c D E f

the F₁ from a cross between these two parents is:

F₁ A b C d e F/a B c D E f

Selfing F₁ will produce an F₂ generation including the followinggenotypes:

    ______________________________________                                        A B c D E f/a b C d e F                                                       A B c D e f/a b C d E F                                                       A B c D e f/a b C d e F                                                       .                                                                             .                                                                             ______________________________________                                    

The number of genotypes in the F₂ is 3⁶ for six segregating loci (729)and will produce (2⁶)-2 possible new inbreds, (62 for six segregatingloci).

Each inbred parent which is used in breeding crosses represents a uniquecombination of genes, and the combined effects of the genes define theperformance of the inbred and its performance in hybrid combination.There is published evidence (Smith, O. S., J. S. C . Smith, S. L. Bowen,R. A. Tenborg and S. J. Wall, TAG 80:833-840 (1990)) that each of theselines are different and can be uniquely identified on the basis ofgenetically-controlled molecular markers.

It has been shown (Hallauer, Arnel R. and Miranda, J. B. Fo.Quantitative Genetics in Maize Breeding, Iowa State University Press,Ames Iowa (1981)) that most traits of economic value in maize are underthe genetic control of multiple genetic loci, and that there are a largenumber of unique combinations of these genes present in elite maizegermplasm. If not, genetic progress using elite inbred lines would nolonger be possible. Studies by Duvick and Russell (Duvick, D. N. Maydica37:69-79 (1992); Russell, W. A. Maydica XXIX:375-390 (1983)) have shownthat over the last 50 years the rate of genetic progress in commercialhybrids has been between 1 and 2% per year.

The number of genes affecting the trait of primary economic importancein maize, grain yield, has been estimated to be in the range of 10-1000.Inbred lines which are used as parents for breeding crosses differ inthe number and combination of these genes. These factors make the plantbreeder's task more difficult. Compounding this is evidence that no oneline contains the favorable allele at all loci, and that differentalleles have different economic values depending on the geneticbackground and field environment in which the hybrid is grown. Fiftyyears of breeding experience shows that there are many genes affectinggrain yield and each of these has a relatively small effect on thistrait. The effects are small compared to breeders' ability to measuregrain yield differences in evaluation trials. Therefore, the parents ofthe breeding cross must differ at several of these loci so that thegenetic differences in the progeny will be large enough that breederscan develop a line that increases the economic worth of its hybrids overthat of hybrids made with either parent.

If the number of loci segregating in a cross between two inbred lines isn, the number of unique genotypes in the F₂ generation is 3^(n) (Example2) and the number of unique inbred lines from this cross is {(2^(n))-2}. Only a very limited number of these combinations are useful. Onlyabout 1 in 10,000 of the progeny from F₂ 's are commercially useful.

By way of example, if it is assumed that the number of segregating lociin F₂ is somewhere between 20 and 50, and that each parent is fixed forhalf the favorable alleles, it is then possible to calculate approximateprobabilities of finding an inbred that has the favorable allele at{(n/2)+m} loci, where n/2 is the number of favorable alleles in each ofthe parents and m is the number of additional favorable alleles in thenew inbred. See Example 2 below. The number m is assumed to be greaterthan three because each allele has so small an effect that evaluationtechniques are not sensitive enough to detect differences due to threeor less favorable alleles. The probabilities in Example 2 are on theorder of 10⁻⁵ or smaller and they are the probabilities that at leastone genotype with (n/2)+m favorable alleles will exist.

To put this in perspective the number of plants grown on 60 millionacres (approximate US corn acreage) at 25000 plants/acre is 1.5×10¹².

EXAMPLE 2 Probability of Finding an Inbred With m of n Favorable Alleles

Assume each parent has n/2 of the favorable alleles and only 1/2 of thecombinations of loci are economically useful.

    ______________________________________                                        no. of  no. favorable                                                                             no. additional                                                                             Probability                                  segregating                                                                           alleles in  favorable alleles                                                                          that genotype                                loci (n)                                                                              Parents (n/2)                                                                             in new inbred                                                                              occurs*                                      ______________________________________                                        20      10          14           3 × 10.sup.-5                          24      12          16           2 × 10.sup.-5                          28      14          18           1 × 10.sup.-5                          32      16          20           8 × 10.sup.-6                          36      18          22           5 × 10.sup.-6                          40      20          24           3 × 10.sup.-6                          44      22          26           2 × 10.sup.-6                          48      24          28           1 × 10.sup.-6                          ______________________________________                                         *Probability that a useful combination exists, does not include the           probability of identifying this combination if it does not exist.        

The possibility of having a usably high probability of being able toidentify this genotype based on replicated field testing would be mostlikely smaller than this, and is a function of how large a population ofgenotypes is tested and how testing resources are allocated in thetesting program.

At Pioneer Hi-Bred International, a typical corn research station has astaff of four, and 20 acres of breeding nursery. Those researchers plantthose 20 acres with 25,000 nursery rows, 15,000 yield test plots in10-15 yield test sites, and one or two disease-screening nurseries.Employing a temporary crew of 20 to 30 pollinators, the station makesabout 65,000 hand pollinations per growing season. Thus, one of thelargest plant breeding programs in the world does not have asufficiently large breeding population to be able to rely upon "playingthe numbers" to obtain successful research results. Nevertheless,Pioneer's breeders at each station produce from three to ten new inbredswhich are proposed for commercial use each year. Over the 32 Pioneerresearch stations in North America, this amounts to from about 100 to300 new inbreds proposed for use, and less than 50 and more commonlyless than 30 of these inbreds that actually satisfy the performancecriteria for commercial use.

This is a result of plant breeders using their skills, experience andintuitive ability to select inbreds having the necessary qualities.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred corn line,designated PHAA0. This invention thus relates to the seeds of inbredcorn line PHAA0, to the plants of inbred corn line PHAA0, and to methodsfor producing a corn plant produced by crossing the inbred line PHAA0with itself or another corn line. This invention further relates tohybrid corn seeds and plants produced by crossing the inbred line PHAA0with another corn line.

DEFINITIONS

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. ABS is in absolute terms and %MN is percent of the mean for the experiments in which the inbred orhybrid was grown.

BAR PLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Actual yield of the grain at harvest inbushels per acre adjusted to 15.5% moisture.

DRP EAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured in inches.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on a perplot basis for the inbred or hybrid.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GRN APP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of the harvested grain, any mold on the grain, and anycracked grain. High scores indicate good grain quality.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in inches.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POL WT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

It should be understood that the inbred can, through routinemanipulation of cytoplasmic factors, be produced in a cytoplasmicmale-sterile form which is otherwise phenotypically identical to themale-fertile form.

PRM=PREDICTED RM. This trait, predicted relative maturity (RM), is basedon the harvest moisture of the grain. The relative maturity rating isbased on a known set of checks and utilizes standard linear regressionanalyses and is referred to as the Comparative Relative Maturity RatingSystem which is similar to the Minnesota Relative Maturity RatingSystem.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that donot root lodge; plants that lean from the vertical axis at anapproximately 30° angle or greater would be counted as root lodged.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A cornbreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

STA GRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plantsper plot.

STK LDG=STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at timeof flowering. A 1 would indicate a very high level of blasting at timeof flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data is given as percentage of tillers:number of tillers per plot divided by number of plants per plot.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain inpounds for a given volume (bushel) adjusted for percent moisture.

YLD=YIELD. It is the same as BU ACR ABS.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

MDM CPX=Maize Dwarf Mosaic Complex (MDMV=Maize Dwarf Mosaic Virus &MCDV=Maize Chlorotic Dwarf Virus): Visual rating (1-9 score) where a "1"is very susceptible and a "9" is very resistant.

SLF BLT=Southern Leaf Blight (Bipolaris maydis, Helminthosporiummaydis): Visual rating (1-9 score) where a "1" is very susceptible and a"9" is very resistant.

NLF BLT=Northern Leaf Blight (Exserohilum turcicum, H. turcicum): Visualrating (1-9 score) where a "1" is very susceptible and a "9" is veryresistant.

COM RST=Common Rust (Puccinia sorghi): Visual rating (1-9 score) where a"1" is very susceptible and a "9" is very resistant.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis): Visual rating (1-9score) where a "1" is very susceptible and a "9" is very resistant.

STW WLT=Stewart's Wilt (Erwinia stewartii): Visual rating (1-9 score)where a "1" is very susceptible and a "9" is very resistant.

HD SMT=Head Smut (Sphacelotheca reiliana): Percentage of plants that didnot have infection.

EAR MLD=General Ear Mold: Visual rating (1-9 score) where a "1" is verysusceptible and a "9" is very resistant. This is based on overall ratingfor ear mold of mature ears without determining specific mold organism,and may not be predictive for a specific ear mold.

ECB DPE=Dropped ears due to European Corn Borer (Ostrinia nubilalis):Percentage of plants that did not drop ears under second brood cornborer infestation.

ECB 2SC=European Corn Borer Second Brood (Ostrinia nubilalis): Visualrating (1-9 score) of post flowering damage due to infestation byEuropean Corn Borer. A "1" is very susceptible and a "9" is veryresistant.

ECB 1LF=European Corn Borer First Brood (Ostrinia nubilalis): Visualrating (1-9 score) of pre-flowering leaf feeding by European Corn Borer.A "1" is very susceptible and a "9" is very resistant.

DETAILED DESCRIPTION OF THE INVENTION

PHAA0 produces hybrids that are high yielding for their maturity. PHAA0is a good female for its maturity and has good specific and generalcombining ability. Hybrids with PHAA0 also exhibit high yield appearanceand superior whole plant yield, and are therefore advantageous both asgrain producing plants and for silage.

Inbred corn line PHAA0 is a yellow, dent corn inbred that provides anacceptable female parental line for producing first generation F1 cornhybrids. PHAA0 is adapted to most regions of North America and Europe,and in fact all of the early corn growing areas in the world, andproduces hybrids with very good yield (both in terms of grain yield andwhole plant yield). PHAA0 hybrids also exhibit superior stay green,which contributes to improved late season plant health and the avoidanceof premature death. The inbred can exhibit some twisting of the whorl invegetative stages V4 through V6 but grows out of it by the time itflowers.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows. Most of the data in theVariety Description information was collected at Johnston, Iowa. Theinbred has been self-pollinated and ear-rowed a sufficient number ofgenerations with careful attention paid to uniformity of plant type toensure homozygosity and phenotypic stability. The line has beenincreased both by hand and in isolated fields with continued observationfor uniformity. No variant traits have been observed or are expected inPHAA0.

Inbred corn line PHAA0, being substantially homozygous, can bereproduced by planting seeds of the line, growing the resulting cornplants under self-pollinating or sib-pollinating conditions withadequate isolation, and harvesting the resulting seed, using techniquesfamiliar to the agricultural arts.

TABLE 1 VARIETY DESCRIPTION INFORMATION INBRED=PHAA0

Type: Dent

Region Best Adapted: Most Regions

A. Maturity: Average Across Maturity Zones

Heat Unit Shed: 1210

Heat Unit Silk: 1220

No. Reps: 19 ##EQU2##

B. Plant Characteristics

Plant height (to tassel tip): 196 cm

Length of top ear internode: 12 cm

Number of ears per stalk: Slight two ear tendency.

Ear height (to base of top ear): 65 cm

Number of tillers: None

Cytoplasm type: Normal

C. Leaf

Color: (B14) Dark Green

Angle from Stalk: 30-60 degrees

Marginal Waves: (WF9) Few

Number of Leaves (mature plants): 17

Sheath Pubescence: (W22) Light

Longitudinal Creases: (OH56A) Few

Length (Ear node leaf): 69 cm

Width (widest point, ear node leaf): 9 cm

D. Tassel

Number lateral branches: 3

Branch Angle from central spike: >45 degrees

Pollen Shed: light based on Pollen Yield Test (69% of experiment means)

Peduncle Length (top leaf to basal branches): 18 cm

Anther Color: Yellow

Glume Color: Green

E. Ear (Husked Ear Data Except When Stated Otherwise)

Length: 15 cm

Weight: 132 gm

Mid-point Diameter: 24 mm

Silk Color: Yellow

Husk Extension (Harvest stage): Medium (barely covering ear)

Husk Leaf: Short (<8 cm)

Taper of Ear: Average

Position of Shank (dry husks): Upright

Kernel Rows: Straight Distinct Number=14

Husk Color (fresh): Light Green

Husk Color (dry): Buff

Shank Length: 16 cm

Shank (No. of internodes): 8

F. Kernel (Dried)

Size (from ear mid-point)

Length: 12 mm

Width: 8 mm

Thick: 5 mm

Shape Grade (% rounds): 20-40% (29% medium round based on Parent TestData)

Pericarp Color: Colorless

Aleurone Color: Homozygous Yellow

Endosperm Color: Yellow

Endosperm Type: Normal Starch

Gm Wt/100 Seeds (unsized): 30 gm

G. Cob

Diameter at mid-point: 24 mm

Strength: Strong

Color: Red

H. Diseases

Common Rust (P. sorghi): Intermediate

Stewart's Wilt (E. stewartii): Resistant

Head Smut (S. reiliana): Higly Resistant

Fusarium Ear Mold (F. moniliforme): Higly Resistant

Gibberella Ear Rot (G. zeae): Susceptible

I. Insects European Corn Borer-1 Leaf Damage (Pre-flowering)Intermediate

The above descriptions are based on a scale of 1-9, 1 being highlysusceptible, 9 being highly resistant.

S (Susceptible): Would generally represent a score of 1-3.

I (Intermediate): Would generally represent a score of 4-5.

R (Resistant): Would generally represent a score of 6-7.

H (Highly Resistant): Would generally represent a score of 8-9. Highlyresistant does not imply the inbred is immune.

J. Variety Most Closely Resembling

Character Inbred

Maturity PHJ40

Usage PHJ40

PHJ40 (PVP Certificate No. 8600133) is a Pioneer Hi-Bred International,Inc. proprietary inbred.

Data for Items B, C, D, E, F, and G is based primarily on a maximum oftwo reps from Johnston, Iowa grown in 1992, plus description informationfrom the maintaining station.

ELECTROPHORESIS RESULTS Isozyme Genotypes for PHAA0

Isozyme data were generated for inbred corn line PHAA0 according to theprocedures described in Stuber, C. W., Wendel, J. F., Goodman, M. M.,and Smith, J. S. C., "Techniques and Scoring Procedures for Starch GelElectrophoresis of Enzymes from Maize (Zea mays L.)", Technical BulletinNo. 286, North Carolina Agricultural Research Service, North CarolinaState University, Raleigh, N.C. (1988).

The data in Table 2 compares PHAA0 with its parents, PHW03 and PHJ40.

                  TABLE 2                                                         ______________________________________                                        ELECTROPHORESIS RESULTS FOR PHAA0                                             AND ITS PARENTS PHW03 AND PHJ40                                                                PARENTS                                                      LOCI    PHAA0          PHW03    PHJ40                                         ______________________________________                                        ACP1    2              2        2                                             ADH1    4              4        4                                             CAT3    9              9        9                                             DIA1    8              12       8                                             GOT1    4              4        4                                             GOT2    4              2        4                                             GOT3    4              4        4                                             IDH1    4              4        4                                             IDH2    6              4        6                                             MDH1    6              6        6                                             MDH2    6              3        6                                             MDH3    16             16       16                                            MDH4    12             12       12                                            MDH5    12             12       12                                            MMM     4              4        4                                             PGM1    9              8        9                                             PGM2    4              4        4                                             PGD1    2              2        3.8                                           PGD2    5              5        5                                             PHI1    4              4        4                                             ______________________________________                                    

EXAMPLES INBRED AND HYBRID PERFORMANCE OF PHAA0

In the examples that follow, the traits and characteristics of inbredcorn line PHAA0 are given as a line in comparison with other inbreds andin hybrid combination. The data collected on inbred corn line PHAA0 ispresented for the key characteristics and traits.

The data in Table 3A shows PHAA0 has higher yield and lower grainharvest moisture and test weight compared to PHFA5. PHAA0 is taller withhigher ear placement and flowers (GDU Shed and GDU Silk) later thanPHFA5. PHAA0 has better seedling vigor and stalk lodging resistance thanPHFA5.

Table 3B compares PHAA0 to PHJ40. PHAA0 has higher yield and grainharvest moisture but lower test weight than PHJ40. PHAA0 is a tallerinbred than PHJ40. PHAA0 has better seedling vigor and higher earlystand count compared to PHJ40. PHAA0 has fewer scattergrain and betterear mold resistance than PHJ40.

Table 3C shows PHAA0 has higher yield and grain harvest moisture thanPHEM9. PHAA0 is a taller inbred compared to PHEM9. PHAA0 flowers (GDUShed and GDU Silk) earlier than PHEM9.

Table 3D compares PHAA0 to PHRE1. PHAA0 has higher yield and grainharvest moisture compared to PHRE1. PHAA0 is a taller inbred with higherear placement and higher early stand count than PHRE1. PHAA0 and PHRE1shed (GDU Shed) similarly but PHAA0 silks (GDU Silk) later than PHRE1.

Table 4A compares PHAA0 to PHFA5 when both were crossed to the sameinbred testers. The PHAA0 hybrids have higher yield and grain harvestmoisture than the PHFA5 hybrids. The PHAA0 hybrids shed (GDU Shed) laterthan the PHFA5 hybrids. The PHAA0 hybrids have better staygreen andseedling vigor than the PHFA5 hybrids, and also exhibit higher earplacement.

Table 4B compares PHAA0 and PHJ40 when both were crossed to the sameinbred testers. The hybrids yield similarly and have similar grainharvest moisture and test weight but the PHAA0 hybrids are taller withhigher ear placement compared to the PHJ40 hybrids.

Table 4C compares PHAA0 to PHEM9 when both were crossed to the sameinbred testers. The PHAA0 and PHEM9 hybrids have similar yield and grainharvest moisture but the PHAA0 hybrids have slightly lower test weight.The PHAA0 hybrids have higher early stand count compared to the PHEM9hybrids.

Table 4D compares PHAA0 to PHRE1 when both were crossed to the sameinbred testers. The PHAA0 hybrids have higher yield, grain harvestmoisture and test weight compared to the PHRE1 hybrids. The PHAA0hybrids have better seedling vigor than the PHRE1 hybrids. The PHAA0 andPHRE1 hybrids have similar plant height but the PHAA0 hybrids have lowerear placement.

Table 5A compares PHAA0 to PHEM9 when both were crossed to the sameinbred. The PHAA0 hybrid has higher yield but lower grain harvestmoisture and test weight compared to the PHEM9 hybrid. The PHAA0 hybridis shorter compared to the PHEM9 hybrid.

Table 5B compares PHAA0 to PHJ40 when both were crossed to the sameinbred. The PHAA0 hybrid has higher yield and grain harvest moisture butlower test weight than the PHJ40 hybrid. The PHAA0 hybrid has higherearly stand count than the PHJ40 hybrid.

Table 5C compares PHAA0 to PHRE1 when both were crossed to the sameinbred. The data shows the PHAA0 hybrid has higher yield, grain harvestmoisture and test weight than the PHRE1 hybrid. The PHAA0 hybrid hasbetter seedling vigor and higher early stand count compared to the PHRE1hybrid. The hybrids have similar ear placement but the PHAA0 hybrid istaller.

Table 5D compares PHAA0 to PHRE1 when both were crossed to the sameinbred, an inbred different than in Table 5C. The PHAA0 hybrid hashigher yield, grain harvest moisture and test weight than the PHRE1hybrid. The PHAA0 hybrid has improved stay green, better seedling vigorand higher early stand count compared to the PHRE1 hybrid.

FIG. 1 compares the yield of PHAA0 and PHFA5. PHAA0 yields better thanPHFA5 in high yield environments but is lower yielding than PHFA5 in lowyield environments.

FIG. 2 compares the yield of PHAA0 and PHJ40. PHAA0 has above averageyield across all environments whereas PHJ40 has below average yieldacross all environments. PHAA0 yields better across all environmentsthan PHJ40 with the differential greater in high yield environments.

FIG. 3 compares the yield of PHAA0 and PHRE1. PHAA0 has above averageyield across all environments and is higher yielding across allenvironments than PHRE1.

                                      TABLE 3A                                    __________________________________________________________________________    PAIRED INBRED COMPARISON DATA                                                 VARIETY #1 - PHAA0                                                            VARIETY #2 - PHFA5                                                            __________________________________________________________________________                BU                                                                         BU ACR                                                                              YLD   EAR                                                                              BAR                                                                              PLT EAR SDG EST                                                                              DRP                                                                              TIL                                                                              GDU GDU POL                                                                              POL                     VAR ACR                                                                              %  SC MST                                                                              SZ PLT                                                                              HT  HT  VGR CNT                                                                              EAR                                                                              LER                                                                              SHD SLK WT WT                 DEPT #   ABS                                                                              MN ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS ABS ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS ABS ABS                                                                              %                  __________________________________________________________________________                                                               MN                 TOTAL                                                                              1   83.0                                                                             113                                                                              6.4                                                                              19.5                                                                             5.7                                                                              97.1                                                                             74.0                                                                              28.7                                                                              6.1 46.9                                                                             99.8                                                                             1.7                                                                              1161                                                                              1160                                                                              90.0                                                                             73                 SUM  2   80.5                                                                             111                                                                              6.1                                                                              20.0                                                                             5.0                                                                              93.7                                                                             70.4                                                                              24.9                                                                              4.6 46.0                                                                             100.0                                                                            3.7                                                                              1111                                                                              1119                                                                              84.4                                                                             71                      LOCS                                                                              22 22 7  26 3  18 26  26  15  39 13 24 27  20  3  3                       REPS                                                                              50 50 7  54 3  23 44  44  21  82 32 42 42  24  6  6                       DIFF                                                                              2.6                                                                              2  0.3                                                                              0.5                                                                              0.7                                                                              3.4                                                                              3.7 3.8 1.5 0.9                                                                              0.2                                                                              2.0                                                                              50  41  5.5                                                                              3                       PROB                                                                              .440                                                                             .594                                                                             .457                                                                             .146                                                                             .184                                                                             .363                                                                             .031+                                                                             .001#                                                                             .007#                                                                             .218                                                                             .132                                                                             .135                                                                             .000#                                                                             .000#                                                                             .787                                                                             .865               __________________________________________________________________________               POL                                                                              TAS                                                                              TAS TEX                                                                              TST GRN SCT STA STK RT  EAR STW ECB ECB                     VAR  SC BLS                                                                              SZ  EAR                                                                              WT  APP GRN GRN LDG LDG MLD WLT 1LF 2SC               DEPT  #    ABS                                                                              ABS                                                                              ABS ABS                                                                              ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS               __________________________________________________________________________    TOTAL 1    5.3                                                                              9.0                                                                              3.7 6.5                                                                              56.8                                                                              6.2 8.3 4.6 97.0                                                                              97.9                                                                              7.8 6.0 4.5 5.3               SUM   2    4.4                                                                              8.5                                                                              3.7 7.3                                                                              58.2                                                                              6.9 8.2 4.9 87.5                                                                              89.6                                                                              8.0 3.0 4.0 4.0                     LOCS 12 2  10  4  22  10  6   8   16  6   5   1   2   2                       REPS 16 3  10  4  50  22  6   15  38  14  5   1   2   4                       DIFF 0.9                                                                              0.5                                                                              0.0 0.8                                                                              1.4 0.8 0.2 0.3 9.4 8.3 0.2 3.0 0.5 1.3                     PROB .053*                                                                            .500                                                                             .000#                                                                             .215                                                                             .004#                                                                             .022+                                                                             .363                                                                              .407                                                                              .002#                                                                             .206                                                                              .621    .795                                                                              .126              __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 3B                                    __________________________________________________________________________    PAIRED INBRED COMPARISON DATA                                                 VARIETY #1 - PHAA0                                                            VARIETY #2 - PHJ40                                                            __________________________________________________________________________               BU  BU  YLD     EAR                                                                              BAR PLT EAR                                                                              SDG EST DRP                                                                              TIL                                                                              GDU GDU                       VAR ACR ACR SC  MST SZ PLT HT  HT VGR CNT EAR                                                                              LER                                                                              SHD SLK                DEPT   #   ABS % MN                                                                              ABS ABS ABS                                                                              ABS ABS ABS                                                                              ABS ABS ABS                                                                              ABS                                                                              ABS ABS                __________________________________________________________________________    TOTAL  1   83.0                                                                              113 6.5 19.5                                                                              5.7                                                                              97.1                                                                              74.3                                                                              29.4                                                                             6.3 47.9                                                                              99.8                                                                             1.5                                                                              1167                                                                              1173               SUM    2   70.5                                                                              96  5.8 18.6                                                                              5.0                                                                              96.4                                                                              66.9                                                                              29.1                                                                             5.4 45.5                                                                              99.8                                                                             1.8                                                                              1160                                                                              1174                      LOCS                                                                              22  22  6   26  3  18  28  28 16  49  13 33 36  29                        REPS                                                                              80  80  6   79  3  31  57  59 34  120 32 71 61  40                        DIFF                                                                              12.6                                                                              17  0.7 0.9 0.7                                                                              0.7 7.4 0.2                                                                              0.8 2.5 0.1                                                                              0.3                                                                              07  01                        PROB                                                                              .000#                                                                             .000#                                                                             .025+                                                                             .022+                                                                             .184                                                                             .606                                                                              .000#                                                                             .774                                                                             .035+                                                                             .000#                                                                             .563                                                                             .628                                                                             .262                                                                              .640               __________________________________________________________________________             POL POL POL                                                                              TAS                                                                              TAS TEX                                                                              TST GRN SCT STA STK                                                                              RT  EAR ECB                                                                              ECB                    VAR WT  WT  SC BLS                                                                              SZ  EAR                                                                              WT  APP GRN GRN LDG                                                                              LDG MLD 1LF                                                                              2SC               DEPT #   ABS % MN                                                                              ABS                                                                              ABS                                                                              ABS ABS                                                                              ABS ABS ABS ABS ABS                                                                              ABS ABS ABS                                                                              ABS               __________________________________________________________________________    TOTAL                                                                              1   85.8                                                                              69  5.3                                                                              9.0                                                                              3.7 6.5                                                                              56.8                                                                              6.2 8.2 4.6 97.0                                                                             97.9                                                                              7.8 4.7                                                                              5.3               SUM  2   106.1                                                                             84  5.0                                                                              9.0                                                                              4.6 7.0                                                                              58.5                                                                              5.8 7.6 4.1 97.2                                                                             97.6                                                                              7.0 4.0                                                                              5.5                    LOCS                                                                              9   9   19 5  9   4  22  10  5   8   16 6   5   5  2                      REPS                                                                              18  18  30 9  9   4  77  22  5   17  42 14  5   8  4                      DIFF                                                                              20.3                                                                              15  0.3                                                                              0.0                                                                              0.9 0.5                                                                              1.7 0.4 0.6 0.5 0.3                                                                              0.3 0.8 0.7                                                                              0.3                    PROB                                                                              .014+                                                                             .017+                                                                             .402                                                                             1.00                                                                             .009#                                                                             .391                                                                             .003#                                                                             .309                                                                              .070*                                                                             .108                                                                              .813                                                                             .530                                                                              .099*                                                                             530                                                                              .910              __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 3C                                    __________________________________________________________________________    PAIRED INBRED COMPARISON DATA                                                 VARIETY #1 - PHAA0                                                            VARIETY #2 - PHEM9                                                            __________________________________________________________________________                YLD   EAR BAR                                                                              PLT                                                                              EAR SDG EST TIL                                                                              GDU GDU POL POL POL                        VAR SC MST                                                                              SZ  PLT                                                                              HT HT  VGR CNT LER                                                                              SHD SLK WT  WT  SC                 DEPT    #   ABS                                                                              ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS ABS ABS ABS                                                                              ABS ABS ABS %                                                                                 ABS                __________________________________________________________________________    TOTAL SUM                                                                             1   6.0                                                                              12.3                                                                             5.7 96.3                                                                             72.7                                                                             29.0                                                                              6.6 32.4                                                                              1.6                                                                              1155                                                                              1172                                                                              76.3                                                                              68  4.9                        2   5.8                                                                              11.9                                                                             5.7 95.7                                                                             71.0                                                                             27.9                                                                              6.0 32.6                                                                              9.3                                                                              1214                                                                              1229                                                                              140.0                                                                             124 6.1                        LOCS                                                                              6  2  3   12 11 11  9   23  14 19  19  3   3   9                          REPS                                                                              6  2  3   12 11 11  9   47  17 22  22  6   6   12                         DIFF                                                                              0.2                                                                              0.3                                                                              0.0 0.6                                                                              1.7                                                                              1.1 0.6 0.1 7.7                                                                              59  57  63.7                                                                              56  1.2                        PROB                                                                              .695                                                                             .500                                                                             .000#                                                                             .803                                                                             .059*                                                                            .303                                                                              .456                                                                              .881                                                                              .149                                                                             .000#                                                                             .000#                                                                             .052*                                                                             .032+                                                                             .077*              __________________________________________________________________________                TAS                                                                              TAS TEX                                                                              SCT STA EAR STW ECB                                             VAR BLS                                                                              SZ  EAR                                                                              GRN GRN MLD WLT 1LF                                     DEPT    #   ABS                                                                              ABS ABS                                                                              ABS ABS ABS ABS ABS                                     __________________________________________________________________________    TOTAL SUM                                                                             1   9.0                                                                              3.6 6.5                                                                              8.2 4.0 7.5 6.0 4.3                                             2   9.0                                                                              5.5 6.0                                                                              7.0 2.0 7.5 6.0 5.5                                             LOCS                                                                              3  8   4  5   1   4   1   5                                               REPS                                                                              5  8   4  5   1   4   1   8                                               DIFF                                                                              0.0                                                                              1.9 0.5                                                                              1.2 2.0 0.0 0.0 1.2                                             PROB                                                                              1.00                                                                             .002#                                                                             .182                                                                             .178    .000#   .282                                    __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 3D                                    __________________________________________________________________________    PAIRED INBRED COMPARISON DATA                                                 VARIETY #1 - PHAA0                                                            VARIETY #2 - PHRE1                                                            __________________________________________________________________________                BU  BU  YLD   EAR                                                                              BAR                                                                              PLT EAR SDG EST DRP                                                                              TIL                                                                              GDU  GDU                        VAR ACR ACR SC MST                                                                              SZ PLT                                                                              HT  HT  VGR CNT EAR                                                                              LER                                                                              SHD  SLK                DEPT    #   ABS % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS ABS ABS ABS ABS                                                                              ABS                                                                              ABS  ABS                __________________________________________________________________________    TOTAL SUM                                                                             1   83.0                                                                              113 6.4                                                                              19.5                                                                             5.7                                                                              97.1                                                                             74.3                                                                              29.4                                                                              6.2 46.0                                                                              99.8                                                                             1.5                                                                              1165 1171                       2   69.9                                                                              96  5.7                                                                              19.0                                                                             4.7                                                                              96.1                                                                             64.6                                                                              26.2                                                                              6.0 43.9                                                                              99.9                                                                             1.5                                                                              1159 1151                       LOCS                                                                              22  22  7  26 3  18 28  28  17  48  13 31 35   28                         REPS                                                                              50  50  7  54 3  23 46  46  23  95  32 53 54   36                         DIFF                                                                              13.2                                                                              18  0.7                                                                              0.5                                                                              1.0                                                                              1.0                                                                              9.7 3.2 0.2 2.1 0.1                                                                              0.0                                                                              06   20                         PROB                                                                              .001#                                                                             .001#                                                                             .094*                                                                            .098*                                                                            .225                                                                             .599                                                                             .000#                                                                             .001#                                                                             .627                                                                              .010+                                                                             .650                                                                             .997                                                                             .469 .010+              __________________________________________________________________________             POL                                                                              POL POL                                                                              TAS                                                                              TAS TEX                                                                              TST GRN SCT STA STK RT  EAR ECB                                                                              ECB                    VAR WT WT  SC BLS                                                                              SZ  EAR                                                                              WT  APP GRN GRN LDG LDG MLD 1LF                                                                              2SC               DEPT #   ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS ABS                                                                              ABS ABS ABS ABS ABS ABS ABS ABS                                                                              ABS               __________________________________________________________________________    TOTAL                                                                              1   84.6                                                                             71  5.3                                                                              9.0                                                                              3.7 6.5                                                                              56.8                                                                              6.2 8.3 4.2 97.0                                                                              97.9                                                                              7.8 4.5                                                                              5.3               SUM  2   88.4                                                                             73  5.5                                                                              9.0                                                                              4.7 5.5                                                                              59.0                                                                              5.9 8.3 3.6 94.8                                                                              89.0                                                                              7.8 5.3                                                                              2.8                    LOCS                                                                              7  7   16 4  10  4  22  10  6   9   16  6   5   4  2                      REPS                                                                              14 14  24 7  10  4  50  22  6   16  38  14  5   4  4                      DIFF                                                                              3.8                                                                              2   0.2                                                                              0.0                                                                              1.0 1.0                                                                              2.2 0.3 0.0 0.6 2.1 8.9 0.0 0.8                                                                              2.5                    PROB                                                                              .655                                                                             .731                                                                              .323                                                                             1.00                                                                             .004#                                                                             .252                                                                             .000#                                                                             .231                                                                              .000#                                                                             .187                                                                              .323                                                                              .111                                                                              .000#                                                                             .215                                                                             .430              __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 4A                                    __________________________________________________________________________    AVERAGE INBRED BY TESTER PERFORMANCE COMPARING PHFA5 TO PHAA0                 CROSSED TO THE SAME INBRED TESTERS AND GROWN IN THE SAME EXPERIMENTS.         ALL VALUES ARE EXPRESSED AS PERCENT OF THE EXPERIMENT MEAN EXCEPT             PREDICTED RM, SELECTION INDEX, AND YIELD (BU/ACR).                            __________________________________________________________________________                     SEL BU          GDU PRM STK RT                                      INBRED                                                                              PRM IND ACR YLD MST SHD SHD LDG LDG                              __________________________________________________________________________    TOTAL  REPLIC.                                                                             91  91  91  91  91  53  10  74  4                                MEAN WTS                                                                             PHFA5 85  105 84  103 93  96  80  101 109                              MEAN WTS                                                                             PHAA0 87  109 89  110 103 100 86  99  78                                      DIFF. 3   4   5   7   10  4   5   1   31                               __________________________________________________________________________                 STA TST GRN SDG EST STK PLT EAR DRP                                     INBRED                                                                              GRN WTA APP VGR CNT CNT HT  HT  EAR                              __________________________________________________________________________    TOTAL  REPLIC.                                                                             4   91  37  97  129 166 75  75  59                               MEAN WTS                                                                             PHFA5 117 103 109 91  100 100 97  89  100                              MEAN WTS                                                                             PHAA0 126 101 100 116 100 100 98  99  100                                     DIFF. 9   1   9   25  0   0   1   10  0                                __________________________________________________________________________

                                      TABLE 4B                                    __________________________________________________________________________    AVERAGE INBRED BY TESTER PERFORMANCE COMPARING PHJ40 TO PHAA0 CROSSED TO      THE SAME INBRED TESTERS AND GROWN IN THE SAME EXPERIMENTS. ALL VALUES ARE     EXPRESSED                                                                     AS PERCENT OF THE EXPERIMENT MEAN EXCEPT PREDICTED RM, SELECTION INDEX,       AND YIELD (BU/ACR).                                                                             SEL                                                                              BU        GDU PRM STK TST EST                                                                              STK                                                                              PLT EAR                                                                              DRP                       INBRED                                                                              PRM IND                                                                              ACR                                                                              YLD                                                                              MST SHD SHD LDG WTA CNT                                                                              CNT                                                                              HT  HT EAR               __________________________________________________________________________    TOTAL   REPLIC.                                                                             6   3  6  6  6   2   3   4   6   3  10 4   4  2                 MEAN WTS                                                                              PHJ40 92  106                                                                              121                                                                              106                                                                              97  100 91  109 99  103                                                                              100                                                                              103 107                                                                              100               MEAN WTS                                                                              PHAA0 92  95 122                                                                              106                                                                              98  99  89  110 98  102                                                                              99 106 109                                                                              100                       DIFF.     11 1  1  1   1   2   1   1   1  1  2   2                    __________________________________________________________________________

                                      TABLE 4C                                    __________________________________________________________________________    AVERAGE INBRED BY TESTER PERFORMANCE COMPARING PHEM9 TO PHAA0                 CROSSED TO THE SAME INBRED TESTERS AND GROWN IN THE SAME EXPERI-              MENTS. ALL VALUES ARE EXPRESSED AS PERCENT OF THE EXPERIMENT                  MEAN EXCEPT PREDICTED RM, SELECTION INDEX, AND YIELD (BU/ACR).                __________________________________________________________________________                     SEL                                                                              BU       GDU PRM STK RT                                          INBRED                                                                              PRM IND                                                                              ACR                                                                              YLD                                                                              MST                                                                              SHD SHD LDG LDG                                  __________________________________________________________________________    TOTAL  REPLIC.                                                                             12  12 12 12 12 11  3   14  2                                    MEAN WTS                                                                             PHEM9 89  105                                                                              109                                                                              105                                                                              92 100 90  99  96                                   MEAN WTS                                                                             PHAA0 89  106                                                                              109                                                                              105                                                                              92 97  86  100 81                                          DIFF.     1     0  0  3   4   1   15                                   __________________________________________________________________________                  TST GRN  SDG EST STK                                                                              PLT EAR                                                                              DRP                                         INBRED WTA APP  VGR CNT CNT                                                                              HT  HT EAR                                  __________________________________________________________________________    TOTAL  REPLIC.                                                                              12  7    13  29  32 15  15 3                                    MEAN WTS                                                                             PHEM9  101 96   97  97  100                                                                              100 97 100                                  MEAN WTS                                                                             PHAA0  99  94   96  100 100                                                                              98  95 100                                         DIFF.  2   3    2   3   0  3   2                                       __________________________________________________________________________

                                      TABLE 4D                                    __________________________________________________________________________    AVERAGE INBRED BY TESTER PERFORMANCE COMPARING PHRE1 TO PHAA0                 CROSSED TO THE SAME INBRED TESTERS AND GROWN IN THE SAME EXPERIMENTS.         ALL VALUES ARE EXPRESSED AS PERCENT OF THE EXPERIMENT MEAN EXCEPT             PREDICTED RM, SELECTION INDEX, AND YIELD (BU/ACR).                            __________________________________________________________________________                     SEL BU          GDU PRM STK RT                                      INBRED                                                                              PRM IND ACR YLD MST SHD SHD LDG LDG                              __________________________________________________________________________    TOTAL  REPLIC.                                                                             294 290 294 294 294 174 41  260 23                               MEAN WTS                                                                             PHRE1 88  102 97  101 98  101 89  100 102                              MEAN WTS                                                                             PHAA0 90  104 100 104 102 100 88  98  94                               __________________________________________________________________________                 STA TST GRN SDG EST STK PLT EAR DRP                                     INBRED                                                                              GRN WTA APP VGR CNT CNT HT  HT  EAR                              __________________________________________________________________________    TOTAL  REPLIC.                                                                             3   294 156 266 405 555 248 248 181                              MEAN WTS                                                                             PHRE1 112 99  98  102 101 100 98  103 100                              MEAN WTS                                                                             PHAA0 112 100 95  110 100 100 97  99  100                              __________________________________________________________________________

                                      TABLE 5A                                    __________________________________________________________________________    VARIETY #1 - PHAA0 HYBRID                                                     VARIETY #2 - PREM9 HYBRID                                                     __________________________________________________________________________                        BU  BU      STK RT  TST                                           VAR     PRM ACR ACR MST LDG LDG WTA                                   DEPT    #   PRM SHD ABS % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                  __________________________________________________________________________    TOTAL SUM                                                                             1   88  86  111.5                                                                             106 91  100 81  99                                            2   89  90  110.7                                                                             105 95  100 96  101                                           LOCS                                                                              4   4   18  18  18  19  1   14                                            REPS                                                                              4   4   24  24  24  25  2   19                                            DIFF                                                                              1   4   0.8 1   5   0   15  2                                             PROB                                                                              .446                                                                              .015+                                                                             .725                                                                              .636                                                                              .068*                                                                             .973    .002#                                 __________________________________________________________________________                GRN SDG EST STK PLT EAR DRP GDU                                           VAR APP VGR CNT CNT HT  HT  EAR SHD                                   DEPT    #   % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                  __________________________________________________________________________    TOTAL SUM                                                                             1   87  96  100 100 97  93  100 97                                            2   103 96  100 100 100 94  100 100                                           LOCS                                                                              11  11  6   23  12  12  3   5                                             REPS                                                                              13  13  7   30  15  15  3   9                                             DIFF                                                                              15  0   0   0   3   1   0   3                                             PROB                                                                              .062*                                                                             .977                                                                              .959                                                                              .541                                                                              .051*                                                                             .633                                                                              1.00                                                                              .012+                                 __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 5B                                    __________________________________________________________________________    VARIETY #1 - PHAA0 HYBRID                                                     VARIETY #2 - PHJ40 HYBRID                                                     __________________________________________________________________________                        BU  BU      STK RT  STA TST                                       VAR     PRM ACR ACR MST LDG LDG GRN WTA                               DEPT    #   PRM SHD ABS % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                              __________________________________________________________________________    TOTAL SUM                                                                             1   87  86  126.1                                                                             109 97  101 83  88  99                                        2   86  86  120.4                                                                             104 95  103 88  85  100                                       LOCS                                                                              11  11  45  45  45  44  4   6   36                                        REPS                                                                              11  11  76  76  77  79  7   13  60                                        DIFF                                                                              1   0   5.7 5   2   3   5   3   1                                         PROB                                                                              .048+                                                                             .516                                                                              .006#                                                                             .009#                                                                             .063*                                                                             .034+                                                                             .307                                                                              .792                                                                              .006#                             __________________________________________________________________________                GRN SDG EST STK PLT EAR DRP BRT GDU                                       VAR APP VGR CNT CNT HT  HT  EAR STK SHD                               DEPT    #   % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                              __________________________________________________________________________    TOTAL SUM                                                                             1   87  99  101 100 99  97  100 101 100                                       2   89  98  99  100 98  98  100 99  99                                        LOCS                                                                              36  31  27  58  28  28  20  1   17                                        REPS                                                                              66  54  52  104 51  51  39  2   33                                        DIFF                                                                              2   1   2   0   1   1   0   1   1                                         PROB                                                                              .462                                                                              .698                                                                              .088*                                                                             .856                                                                              .419                                                                              .439                                                                              .756    .160                              __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 5C                                    __________________________________________________________________________    VARIETY #1 - PHAA0 HYBRID                                                     VARIETY #2 - PHRE1 HYBRID                                                     __________________________________________________________________________                        BU  BU      STK RT  TST                                           VAR     PRM ACR ACR MST LDG LDG WTA                                   DEPT    #   PRM SHD ABS % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                  __________________________________________________________________________    TOTAL SUM                                                                             1   88  86  109.3                                                                             108 96  102 65  99                                            2   87  87  104.2                                                                             103 92  104 98  98                                            LOCS                                                                              7   8   27  27  27  28  2   18                                            REPS                                                                              7   8   39  39  39  45  3   23                                            DIFF                                                                              1   0   5.1 5   4   2   34  2                                             PROB                                                                              .121                                                                              .589                                                                              .035+                                                                             .035+                                                                             .036+                                                                             .158                                                                              .263                                                                              .006#                                 __________________________________________________________________________                GRN SDG EST STK PLT EAR DRP GDU                                           VAR APP VGR CNT CNT HT  HT  EAR SHD                                   DEPT    #   % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                  __________________________________________________________________________    TOTAL SUM                                                                             1   85  100 100 100 98  96  100 100                                           2   94  87  92  100 96  95  100 100                                           LOCS                                                                              18  19  11  38  17  17  8   12                                            REPS                                                                              29  29  17  61  27  27  13  24                                            DIFF                                                                              9   13  9   0   3   0   0   0                                             PROB                                                                              .102                                                                              .008#                                                                             .001#                                                                             .429                                                                              .028+                                                                             .870                                                                              .196                                                                              .909                                  __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

                                      TABLE 5D                                    __________________________________________________________________________    VARIETY #1 - PHAA0 HYBRID                                                     VARIETY #2 - PHRE1 HYBRID                                                     __________________________________________________________________________                        BU  BU      STK RT  STA TST                                       VAR     PRM ACR ACR MST LDG LDG GRN WTA                               DEPT    #   PRM SHD ABS % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                              __________________________________________________________________________    TOTAL SUM                                                                             1   89  90  135.1                                                                             111 94  95  103 125 100                                       2   88  91  127.4                                                                             105 92  101 102 108 99                                        LOCS                                                                              13  12  44  44  44  42  2   5   40                                        REPS                                                                              13  12  70  70  70  70  4   11  65                                        DIFF                                                                              1   2   7.7 6   3   6   1   17  0                                         PROB                                                                              .158                                                                              .066*                                                                             .000#                                                                             .001#                                                                             .066*                                                                             .001#                                                                             .890                                                                              .246                                                                              .497                              __________________________________________________________________________                GRN SDG EST STK PLT EAR DRP BRT GDU                                       VAR APP VGR CNT CNT HT  HT  EAR STK SHD                               DEPT    #   % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                              __________________________________________________________________________    TOTAL SUM                                                                             1   96  114 102 100 98  102 100 101 100                                       2   100 103 99  100 98  104 100 101 100                                       LOCS                                                                              34  31  31  55  27  27  20  1   18                                        REPS                                                                              59  53  61  93  47  47  35  2   34                                        DIFF                                                                              4   11  3   0   0   2   0   0   1                                         PROB                                                                              .151                                                                              .006#                                                                             .035+                                                                             .641                                                                              .556                                                                              .443                                                                              1.00    .024+                             __________________________________________________________________________     *= 10% SIG                                                                    += 5% SIG                                                                     #= 1% SIG                                                                

INDUSTRIAL APPLICABILITY

The foregoing is set forth by way of example and is not intended tolimit the scope of the invention.

This invention also is directed to methods for producing a corn plant bycrossing a first parent corn plant with a second parent corn plantwherein the first or second parent corn plant is an inbred corn plantfrom the line PHAA0. Further, both first and second parent corn plantscan come from the inbred corn line PHAA0. Thus, any such methods usingthe inbred corn line PHAA0 are part of this invention: selfing,backcrosses, hybrid production, crosses to populations, and the like. Italso would include more unconventional methods of combining the inbredwith another such as using various culturing techniques known to thoseskilled in the art. All plants produced using inbred corn line PHAA0 asa parent are within the scope of this invention. Advantageously, theinbred corn line is used in crosses with other, different, corn inbredsto produce first generation (F₁) corn hybrid seeds and plants withsuperior characteristics.

Corn plants (Zea mays L.) can be bred by both self-pollination andcross-pollination techniques. Corn has male flowers, located on thetassel, and female flowers, located on the ear, on the same plant.Natural pollination occurs in corn when wind blows pollen from thetassels to the silks that protrude from the tops of the incipient ears.Backcrossing can be used to transfer monogenic traits from one line toanother. This can be accomplished for example by first crossing asuperior inbred (A) (recurrent parent) to a donor inbred (non-recurrentparent), which carries the appropriate gene(s) for the trait inquestion. The progeny of this cross is then mated back to the superiorrecurrent parent (A) followed by selection in the resultant progeny forthe desired trait to be transferred from the non-recurrent parent. Afterfive or more backcross generations with selection for the desired trait,the progeny will be heterozygous for loci controlling the characteristicbeing transferred, but will be like the superior parent for most oralmost all other genes. The last backcross generation would be selfed togive pure breeding progeny for the gene(s) being transferred.

Hybrid corn seed is produced by planting male and female parental linesin sufficient proximity to permit pollination of the female line by themale line ("pollinating proximity"). To assure genetic uniformity andavoid self-pollination, steps are taken to prevent pollen formation bythe plants of the parental line chosen to serve as the female. This ismost commonly done by manual detasseling. Alternate strips of theparental lines of corn are planted in a field, and the pollen-bearingtassels are physically removed from the female plants, either by hand orby machine. Providing that there is sufficient isolation from othersources of corn pollen, the ears of the female plants will be fertilizedonly by pollen from the male plants, and the resulting seed is thereforehybrid and will form hybrid plants. In a single-cross hybrid, bothparents are inbred lines. In a double-cross hybrid, both parents are theF₁ offspring of a cross of two inbred lines. In a three-way cross, oneof the parents is an inbred line and the other parent is an F₁ hybrid.Each cross is made in the manner described herein.

Unfortunately, the manual detasseling process is not entirely reliable.Occasionally a female plant will be blown over by a storm and escapedetasseling. Or, a detasseler will not completely remove the tassel ofthe plant. In either event, the female plant will successfully shedpollen and some female plants will be self-pollinated. This will resultin seed of the female inbred being harvested along with the hybrid seedwhich is normally produced.

Alternatively, the female inbred can be mechanically detasseled.Mechanical detasseling is approximately as reliable as manualdetasseling, but is faster and less costly. However, most detasselingmachines produce more damage to the plants than manual detasseling.

The laborious detasseling process can be avoided by using cytoplasmicmale-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile (donot form pollen) as a result of cytoplasmic factors resulting from thecytoplasmic, as distinguished from the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent, sincethe female parent provides the cytoplasm of the fertilized seed. CMSplants are fertilized with pollen from another inbred that is notmale-sterile. Pollen from the male parent may or may not contributegenes that make the hybrid plants male-fertile. Usually seed fromdetasseled normal maize and CMS-produced seed of the same hybrid must beblended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There can be other drawbacks to CMS. One is an historically observedassociation of a specific variant of CMS with susceptibility to certaincrop diseases. This problem has led to widespread abandonment of use ofthat CMS variant in producing hybrid maize. In addition, CMS sometimeshas a negative association with agronomic performance, particularly inthe areas of stalk quality, early seedling vigor, and yield. Finally,CMS sometimes exhibits the potential for breakdown of sterility incertain environments, rendering CMS lines unreliable for hybrid seedproduction.

Another form of sterility, genic male sterility, is disclosed in U.S.Pat. Nos. 4,654,465 and 4,727,219 to Brar et al. However, this form ofgenetic male sterility requires maintenance of multiple mutant genes atseparate locations within the genome and requires a complex markersystem to track the genes and make use of the system convenient.

Another form of male sterility is imparted in a manner by whichexpression of a transgene produces a "pollen-toxic" compound whichblocks pollen formation in some manner.

Still another form of genetic male sterility uses an inducible promoterto regulate expression of a gene which is known to be critical inmicrosporogenesis, i.e., the production of pollen. The selected gene iscloned, its native promoter removed, and the modified gene is insertedinto an expression sequence with an inducible promoter responsive toexternal control. Preferably, the promoter is one which responds toapplication of a specific non-phytotoxic chemical to the plant.

Using transformation and gene substitution, the "critical" gene isdeleted from the genome of the plant and replaced by thegenetically-engineered gene incorporated into the expression sequencewith the inducible promoter. In this method, the inducible promoter isused to induce fertility, not sterility. The selected gene's promotersequences are removed so that the gene is not transcribed and the plantis male sterile. When it is desired to increase the male-sterile plant,male fertility is restored by inducing expression of the critical genewith a specific non-phytotoxic chemical. Any of the foregoing methodsand combinations thereof can be used to prevent pollen formation by thefemale parent of the hybrid.

As used herein, the term plant includes plant cells, plant protoplasts,plant cell tissue cultures from which corn plants can be regenerated,plant calli, plant clumps, and plant cells that are intact in plants orparts of plants, such as embryos, pollen, flowers, kernels, ears, cobs,leaves, husks, stalks, roots, root tips, anthers, silks, and the like.

Duncan, Williams, Zehr, and Widholm, Planta, (1985) 165:322-332 reflectsthat 97% of the plants cultured which produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus which produced plants. In a furtherstudy in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions which enhance regenerabilityof callus of two inbred lines. Other published reports also indicatedthat "nontraditional" tissues are capable of producing somaticembryogenesis and plant regeneration. K. P. Rao, et al., Maize GeneticsCooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesisfrom glume callus cultures and B. V. Conger, et al., Plant Cell Reports,6:345-347 (1987) indicates somatic embryogenesis from the tissuecultures of maize leaf segments. Thus, it is clear from the literaturethat the state of the art is such that these methods of obtaining plantsare, and were, "conventional" in the sense that they are routinely usedand have a very high rate of success.

Tissue culture of corn is described in European Patent Application,publication 160,390, incorporated herein by reference. Corn tissueculture procedures are also described in Green and Rhodes, "PlantRegeneration in Tissue Culture of Maize," Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Va. 1982, at367-372) and in Duncan, et al., "The Production of Callus Capable ofPlant Regeneration from Immature Embryos of Numerous Zea MaysGenotypes," 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce corn plants having the physiological and morphologicalcharacteristics of the inbred line PHAA0.

Corn is used as human food, livestock feed, and as raw material inindustry. The food uses of corn, in addition to human consumption ofcorn kernels, include both products of dry- and wet-milling industries.The principal products of corn dry milling are grits, meal and flour.The corn wet-milling industry can provide corn starch, corn syrups, anddextrose for food use. Corn oil is recovered from corn germ, which is aby-product of both dry- and wet-milling industries.

Corn, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of corn are mainly from corn starch in the wet-millingindustry and corn flour in the dry-milling industry. The industrialapplications of corn starch and flour are based on functionalproperties, such as viscosity, film formation, adhesive properties, andability to suspend particles. The corn starch and flour have applicationin the paper and textile industries. Other industrial uses includeapplications in adhesives, building materials, foundry binders, laundrystarches, explosives, oil-well muds, and other mining applications.

Plant parts other than the grain of corn are also used in industry.Stalks and husks are made into paper and wallboard and cobs are used forfuel and to make charcoal.

The seed of inbred corn line PHAA0, the plant produced from the inbredseed, the hybrid corn plant produced from the crossing of the inbred,hybrid seed, and various parts of the hybrid corn plant can be utilizedfor human food, livestock feed, and as a raw material in industry.

Although the foregoing invention has been described in some detail byway of illustration and example for the purposes of clarity andunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the invention, as limited only bythe scope of the appended claims.

DEPOSITS

Applicant has made a deposit of at least 2500 seeds of Inbred Corn LinePHAA0 with the American Type Culture Collection (ATCC), Rockville, M.d.20852 USA, ATCC Deposit No. 97658. The seeds deposited with the ATCC onJul. 15, 1996 were taken from the deposit maintained by Pioneer Hi-BredInternational, Inc., 700 Capital Square, 400 Locust Street, Des Moines,Iowa 50309-2340 since prior to the filing date of this application. Thisdeposit of the Inbred Corn Line PHAA0 will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the effective life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicant has satisfied allthe requirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample. Applicant imposes norestrictions on the availability of the deposited material from theATCC; however, Applicant has no authority to waive any restrictionsimposed by law on the transfer of biological material or itstransportation in commerce. Applicant does not waive any infringement ofits rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.). Applicant has applied for U.S.Plant Variety Protection of PHAA0 under Application No. 9400091.

What is claimed is:
 1. Inbred corn seed designated PHAA0 and having thegenotype of ATCC Accession No.
 97658. 2. A corn plant and its partsproduced by the seed of claim
 1. 3. A tissue culture of regenerablecells of a plant according to claim 2 wherein the tissue cultureregenerates plants having all the physiological and morphologicalcharacteristics of PHAA0 having ATCC Accession No.
 97658. 4. A tissueculture according to claim 3, the tissue culture selected from the groupconsisting of leaves, pollen, embryos, roots, root tips, anthers, silk,flowers, kernels, ears, cobs, husks and stalks, and cells andprotoplasts thereof.
 5. A corn plant regenerated from the tissue cultureof claim 3 and having all the physiological and morphologicalcharacteristics of PHAA0 having ATCC Accession No.
 97658. 6. A processto produce a novel hybrid corn seed which gives rise to a hybrid cornplant having alleles which, when expressed, contribute to hybrids whichare adapted to the northern corn growing regions of North America andwhich exhibit the traits of high yield, very good stay green andsuperior whole plant yield, compared to similarly adapted hybrids,comprising the steps of:(a) planting, in pollinating proximity, seed oftwo parental lines, one of the parental lines being PHAA0, having ATCCAccession No. 97658, and the other parental line having a genotypedifferent from PHAA0; (b) cultivating corn plants resulting from saidplanting; (c) preventing pollen formation by the plants of one of theparental lines; (d) allowing natural cross pollinating to occur betweensaid parental lines; and (e) harvesting seeds produced by the plantswhich do not form pollen.
 7. Hybrid seed produced by:(a) planting, inpollinating proximity, seeds of two parental lines, one of the parentallines being PHAA0, having ATCC Accession No. 97658, and the otherparental line having a genotype different from PHAA0; (b) cultivatingcorn plants resulting from said planting; (c) preventing pollenformation by the plants of one of the parental lines; (d) allowingnatural cross pollinating to occur between said parental lines; and (e)harvesting seeds produced by the plants which do not form pollen. 8.Hybrid seed produced by hybrid combination of plants of inbred corn seeddesignated PHAA0 and having ATCC Accession No. 97658 and plants of agenotype different from PHAA0.
 9. Hybrid plant, and its parts, grownfrom seed of claim
 8. 10. A tissue culture of the regenerable cells ofthe corn plant of claim 9.